Narcoterrorism is an increasing threat to international security and its reach extends across the globe to areas in the Caucasus, Balkans, Asia, the Middle East, and Latin America. Linkages between terrorist and narco-organisations, engaged in cultivation, processing and trafficking of illicit drugs, are real and driven by “convenience” and profit. This book analyses narcoterrorism as a growing threat to international security. It focuses on aspects such as specific changes in the international security environment; a conceptual framework of narcoterrorism; and the challenges of dealing with complex phenomena. Two case studies – Colombia and Afghanistan – are discussed in order to illustrate the relationship between the drug industry and terrorism. The reasons for limited success in responding to the narcoterrorist threat are also clarified, as well as the direction to be pursued in order to achieve greater success in countering this threat. The importance of the work will be in its clarification of what constitutes the threat of narcoterrorism for policy makers, the intelligence community and anyone researching the phenomenon.